Change frame or New bike? (Looking for Northeast Gravel Rider feedback)

[dmortimer]

I joined the paceline forum as I had seen so many D2R2 posts here... So I'm hoping for some guidance from other Northeast gravel riders.

I have ridden my upgraded Nashbar CX1 in the 2018 Farmers Daughter Gravel Grinder and in 2018 100k D2R2. For 2019, I'm going to repeat Farmers Daughter and do the new route, 160K, D2R2.

The bike is a nine speed - sora shifters, then a SHUN crankset in which the small ring is a TA 33 tooth. The rear cassette is a 12-36 shimano and the rear mech is the nine speed deore mtn bike model. Everything else has been changed from stock as well - brakes are trp cx 8.4, I've got salsa cowbell bars, FSA SLK seatpost, a saddle that fits me, etc. (Its also my winter road bike run with 32mm gatorskins).

In short, my gravel bike is ever a work in progress with small upgrades and changes to make it more flexible and more forgiving of steep terrain. I invested a ton of time last summer into figuring out the TA 33mm ring and the 12-36/deore rear mech. I ride this bike a fair amount in the summer in the Catskills, mostly on dirt rail trails, and in Southern NH on a combination of local roads (dirt and paved - sometimes not well maintained dirt - and trail).

Last year at Farmer's Daughter, the conditions were rough and I felt the lack of a larger tire. I finished but it was tough. I was running Schwalbe CX Comp 38mm, which are great value tires, but I'd like to fit something wider with more knobs if needed. Wider doesn't fit in the nashbar frame all that well, specifically the rear triangle. I could probably push to a 40mm tire with small knobs but past that, it isn't going to have enough clearance for mud.

I'm weighing the following two options:

A) Buying a cross check frameset for about $500, to open up wider tire clearance and just moving all the other components. (Or trying to find a frameset/bike cheaper...)

B) Spending a lot more money and buying a used gravel bike with clearance for wider tires (probably a 650b wheelset) which would probably include disc brakes.

I'm cheap - I'm a teacher, I've got kids, I don't want to spend more than I need to. I'm not looking necessarily for someone to say "Choose A" or "Choose B." I'm looking for anyone to weigh in with pros/cons, suggestions of other framesets (other 700c/29in canti framesets that can take a 68mm english bottom bracket) besides older SOMA doublecross framesets (I know about that option already) or suggestions that I haven't thought of. A consideration is that a 9 speed bike with mini-v brakes is sort of limited and since I'm 35 years old and intend to keep biking, maybe spending money on a cross check frameset isn't a great investment over, say, a 5 year period. Good for one or two years, maybe not more. (Maybe I should pony up and buy a midnight special instead.)

In short - keep the current bike and deal with narrower tire limitations, swap to a surly cross check to open up more tire options, buy a new to me used gravel bike. What would you think about? Am I missing anything?

Thank you paceline forum friends!